Raised floor pedestals and stringers form the supporting understructure beneath a raised access floor. Adjustable pedestals establish the finished floor height and transfer loads toward the structural subfloor, while stringers—when included in the selected system—connect pedestal heads to create a more rigid supporting grid.
The understructure should never be treated as a minor accessory. Pedestal type, adjustment range, head and base design, stringer configuration, corrosion protection, floor height, lateral stability and project loading all influence the performance of the complete raised flooring system.
A conventional raised access floor is supported by adjustable pedestals positioned beneath panel corners. Some systems also use horizontal stringers between pedestal heads. Higher, heavier-duty or specially engineered floors may require reinforced pedestals, larger base plates, stronger tubes or additional lateral/seismic bracing.
What Is a Raised Floor Understructure?
The understructure is the supporting assembly installed between the structural slab and the raised floor panels. Its purpose is to establish the required finished floor level, support the modular panels and provide a stable platform above the underfloor service space.
Depending on the floor system, the understructure may include:
- adjustable pedestal assemblies;
- pedestal heads;
- threaded rods or screws;
- locking nuts;
- base plates;
- vertical tubes;
- stringers;
- panel-locking screws;
- pedestal adhesive or mechanical fixing;
- lateral bracing; and
- seismic bracing where specifically engineered.
What Is a Raised Floor Pedestal?
A raised floor pedestal is an adjustable vertical support positioned beneath the panel grid. In a conventional 600 × 600 mm access floor, panel corners meet above pedestal heads so adjacent panels share the supporting grid.
Pedestals normally include a base, vertical body, threaded adjustment mechanism and head. The exact construction varies considerably between low-profile office systems, conventional technical floors, high-load floors and high-finished-floor-height applications.
A pedestal must do more than simply hold the floor up. The selected assembly should remain level, resist unwanted movement, maintain its height setting and work correctly with the panel and stringer geometry specified by the manufacturer.
Main Components of an Adjustable Raised Floor Pedestal
Pedestal Head
Supports panel corners and may include holes, tabs, gaskets, stringer connections or locking points depending on system design.
Threaded Rod / Screw
Provides controlled vertical adjustment so installers can establish the specified finished floor level.
Lock Nut
Locks the selected pedestal height and helps prevent unintended adjustment or vibration-related movement.
Tube / Support Body
Forms the primary vertical load-transfer component between the pedestal head and base.
Base Plate
Provides the interface between the pedestal assembly and the underlying structural floor.
Bracing Connection
Heavy-duty or seismic assemblies may incorporate dedicated connections for lateral braces.
What Are Raised Floor Stringers?
Stringers are horizontal members installed between pedestal heads on raised access floor systems designed to use them.
Their exact shape and connection method vary. Some systems use screwed stringers, while others use snap-on arrangements that engage directly with the pedestal head.
Stringers can help:
- connect adjacent pedestal assemblies;
- form a defined modular supporting grid;
- increase lateral rigidity on applicable systems;
- improve resistance to panel movement;
- support specified loading configurations; and
- maintain system stability when panels are removed for access.
Important: stringers are not universally required. Some access-floor systems are specifically designed as stringerless or corner-lock systems. Always follow the tested manufacturer’s configuration instead of adding or deleting stringers independently.
Stringered vs Stringerless Raised Floor Systems
| Feature | Stringered System | Stringerless / Corner-Lock System |
|---|---|---|
| Horizontal Members | Stringers connect pedestal heads. | No conventional continuous stringer grid. |
| Panel Support | Panels interact with pedestal heads and stringer grid. | Panels are primarily supported at pedestal heads/corners according to system design. |
| Lateral Rigidity | Stringers can add rigidity to the specified assembly. | Rigidity depends on panel locking and pedestal-head system. |
| Underfloor Access | Panels remain removable; stringer grid remains below. | Potentially less horizontal structure between pedestal heads. |
| Selection | Use where required by tested product specification. | Use only when manufacturer system is designed and tested without stringers. |
Main Types of Raised Floor Pedestals
Pedestal terminology varies by manufacturer. For practical project selection, the main differences usually relate to head geometry, vertical body construction, adjustment range, material, load requirement and whether stringers or bracing are incorporated.
Flat-Head Pedestals
Broad steel top plates supporting panels and/or stringers in conventional technical raised-floor systems.
Snap-On Pedestals
Specialized heads allow compatible stringers to engage directly, reducing or eliminating some screw connections depending on the system.
Heavy-Duty Pedestals
Reinforced tubes, heads and base plates for higher loads, higher floor elevations or project-specific structural requirements.
Low-Profile Pedestals
Short pedestal assemblies used where only a shallow service void is required, particularly in network or office flooring.
Aluminum Pedestals
Specialist understructures used with compatible aluminum access floor systems and cleanroom/technical applications.
Seismic / Braced Pedestals
Heavy-duty pedestal systems combined with stringers and lateral braces when engineered resistance to lateral movement is needed.
Flat-Head Pedestal with Stringer
The HT FS800 manufacturer specification documents a conventional flat-head pedestal system using a square steel top plate, threaded adjustment and a steel vertical tube.
HT Manufacturer Example — Flat-Head Pedestal
| Top Plate | 3.0 mm thick × 75 mm square |
|---|---|
| Adjustment Screw | M19 |
| Base Plate | 2.0 mm thick × 95 / 100 mm square |
| Tube | 22 mm tube × 1.5 mm wall thickness |
| Configuration | Pedestal with stringer |
These dimensions are manufacturer-specific examples from the documented HT FS800 understructure and should not be treated as a universal specification for every raised floor.
Snap-On Pedestal with Stringer
A snap-on system uses a pedestal head designed so compatible stringers can engage directly with the head rather than relying entirely on conventional screwed stringer connections.
The HT documentation describes a snap-on configuration using a die-cast aluminum head, steel base plate and solid threaded rod.
| HT Snap-On Component | Manufacturer-Documented Detail |
|---|---|
| Top Head | Die-cast aluminum head |
| Base Plate | 2.0 mm thick × 95 / 100 mm square |
| Threaded Rod | M16 / M18 / M20 solid full-threaded rod |
| Stringer Connection | Compatible stringer can engage directly with pedestal head without a screw connection in the documented arrangement |
Heavy-Duty Raised Floor Pedestals
As floor height or structural demand increases, a standard pedestal may no longer be the appropriate choice. Heavy-duty pedestal systems can use thicker top plates, larger base plates, wider vertical tubes and thicker tube walls.
The HT FS800 documentation provides a clear example:
| Component | HT Heavy-Duty Example |
|---|---|
| Top Plate | 3.0 / 4.0 mm thick × 75 mm square |
| Adjustment Screw | M19 |
| Base Plate | 3.0 / 4.0 mm thick × 125 / 150 mm square |
| Tube Diameter | 32 / 38 / 48 mm |
| Tube Wall | 1.5 / 2.0 mm |
| Manufacturer Application Note | High-load systems or finished floor heights above approximately 600 mm |
Increasing finished floor height changes the geometry and lateral behaviour of the understructure. At greater heights, the project may require heavier pedestals, larger bases, stronger stringers or engineered bracing depending on system design and project requirements.
Seismic Pedestal & Bracing Systems
A seismic or laterally braced raised-floor system introduces additional structural members intended to resist horizontal movement in addition to normal vertical floor loading.
Huateng’s manufacturer documentation describes its seismic arrangement as a system comprising:
- heavy-duty pedestals;
- stringers; and
- additional bracing members.
The manufacturer notes that this type of configuration is intended particularly for very high systems or seismic applications.
Engineering distinction: simply adding diagonal braces does not automatically make a raised floor “seismic certified.” Seismic requirements should be based on the applicable structural design criteria, project specification and an approved manufacturer/engineering solution.
Raised Floor Pedestal Height & Finished Floor Height
Finished Floor Height (FFH) is the vertical distance from the structural subfloor to the top surface of the completed raised floor.
Pedestal selection should begin only after the required FFH is understood.
The required height may be driven by:
- power cables;
- data cables;
- cable trays;
- floor boxes;
- pipework or other approved services;
- underfloor-air requirements;
- door thresholds;
- adjacent finished-floor levels;
- ramps and steps;
- equipment interfaces; and
- maintenance-access requirements.
Manufacturer Adjustment Requirements in the HT FS800 Specification
The FS800 specification states that for finished floor heights of 150 mm and above, the pedestal assembly should provide a vertical adjustment range of at least ±25 mm without requiring rotation of the pedestal head.
For finished floor heights below 150 mm, the same specification calls for at least ±10 mm adjustment.
These values belong to the documented HT system specification. Other manufacturers and floor systems may use different adjustment ranges and pedestal constructions.
What About Low-Profile Raised Floor Pedestals?
Not every project needs a deep technical plenum. Office and network flooring can use much shallower support systems when the primary objective is power/data distribution rather than large cable trays or underfloor HVAC.
Huateng currently offers low-profile network-floor configurations with pedestals starting around 35 mm on specific systems. These products use different geometry from a conventional tall data-center pedestal and should be treated as a separate engineered floor configuration.
Low-profile solutions can be useful where:
- ceiling height must be preserved;
- only power/data routing is required;
- office refurbishment has limited level difference;
- large underfloor mechanical services are not required; and
- the selected network-floor system is approved for the project.
How Is Pedestal Load Performance Evaluated?
Panel load and pedestal load are not the same measurement.
A raised-floor system can have:
- a panel concentrated-load rating;
- rolling-load requirements;
- uniform/distributed-load performance;
- ultimate panel capacity;
- pedestal axial capacity;
- pedestal overturning resistance; and
- complete-system lateral or seismic requirements.
HT FS800 Pedestal Test Example
The manufacturer specification for the HT FS800 understructure provides separate pedestal structural tests rather than simply quoting the panel load.
| Pedestal Axial Load Test | 10,000 lb / 44,800 N per pedestal |
|---|---|
| Pedestal Overturning Moment Test | 1,000 inch-pounds / approximately 113 N·m per pedestal |
| FS800 Panel Concentrated Design Load | 800 lb / 3.56 kN |
| FS800 Ultimate Panel Load | 2,530 lb / 11.25 kN |
These are different tests measuring different parts or behaviours of the complete floor. They should not be combined or converted into one generic “load capacity” number.
Corrosion Protection for Raised Floor Understructures
Raised floor pedestals spend their service life in a concealed void, so corrosion protection is an important specification issue, especially where environmental conditions may be demanding.
The HT documentation lists multiple understructure finish options, including:
- yellow/golden zinc galvanizing;
- white/silver zinc galvanizing;
- black epoxy coating;
- hot-dip galvanizing; and
- Dacromet-type protective treatment.
The correct finish should be chosen from the project environment, specification and manufacturer recommendation.
Saudi Arabia Considerations
For Saudi projects, the underfloor environment should be evaluated rather than assuming all indoor applications are identical. Relevant considerations can include:
- coastal exposure where applicable;
- humidity;
- construction-stage moisture;
- subfloor condition;
- HVAC operating conditions;
- chemical or industrial exposure;
- expected design life; and
- specified corrosion-protection system.
How Are Raised Floor Pedestals & Stringers Installed?
Installation should follow the manufacturer’s approved method and project drawings. In general, the process includes setting a datum, establishing finished floor height, locating the pedestal grid, leveling the supports and progressively installing panels.
Remove construction debris and verify that the substrate is suitable for the specified pedestal fixing method.
Survey the room, identify high and low points and establish the approved FFH from drawings.
Position the grid so panel joints, perimeter cuts, doors, ramps and fixed building features are properly coordinated.
Use the threaded adjustment system and leveling equipment to establish the required plane.
Screw or snap compatible stringers onto pedestal heads according to the manufacturer system.
Progressively install panels while checking alignment, joint consistency, flatness and stability.
Secure locking components once the correct finished level has been achieved.
Coordinate cut panels, perimeter supports, ramps, floor boxes, cable openings and other approved accessories.
Installation Tolerance in the FS800 Specification
The manufacturer specification requires the installed access floor to remain rigid and free from vibration or rocking panels, with the completed floor maintained within approximately ±3.0 mm level over the entire space.
The same document requires panels to be accurately cut around permanent building features and states that whole panels should remain interchangeable for future underfloor access.
What Conditions Are Required Before Pedestal Installation?
The understructure cannot compensate for every construction-site problem. The FS800 manufacturer’s project specification calls for a clean subfloor, clear access and dry secure storage before installation.
It also specifies an installation environment of approximately:
- 5°C to 32°C temperature; and
- 20% to 70% relative humidity.
Where pedestal adhesive is used, any concrete sealer on the structural slab should be compatible with the specified adhesive.
Electrical grounding requirements should also be coordinated with the electrical contractor rather than assumed to be part of the physical pedestal installation alone.
Do Different Raised Floor Panels Use Different Pedestals?
Yes. Pedestal heads and supporting systems can differ according to the panel family.
Huateng’s current understructure range includes configurations for:
- steel cementitious raised floors;
- woodcore raised floors;
- calcium sulphate raised floors;
- aluminum raised floors; and
- heavy-duty technical floors.
Head dimensions, panel locking, stringer connection, pedestal material and floor height should therefore be coordinated with the exact panel system rather than selected independently.
For an overview of these different panel technologies, read Kayan Gulf’s comparison of raised floor system types .
How to Select Raised Floor Pedestals & Stringers
Steel cementitious, woodcore, calcium sulphate, aluminum and other systems can require different pedestal heads.
Do not specify an understructure before confirming the required service void and architectural levels.
Check equipment loads, rolling loads, pedestal capacity, lateral requirements and the manufacturer’s tested system.
Follow the complete tested product configuration rather than adding or removing stringers solely for cost reasons.
Higher installations may require heavy-duty components or bracing.
Match galvanizing/coating requirements to the project environment and specification.
Confirm pedestal fixing, subfloor preparation, adjustment, perimeter details and installation tolerances.
Compare the actual head plate, base plate, tube, threaded adjustment, stringer and bracing specifications before approval.
What Should a Raised Floor Understructure BOQ or RFQ Include?
A quotation request for raised flooring should define more than the panel area. For the understructure, provide:
- total raised-floor area;
- panel type and dimensions;
- finished floor height;
- minimum and maximum height variation;
- pedestal type;
- pedestal material;
- head/base requirements;
- stringer requirement and type;
- heavy-duty zones;
- equipment loads;
- rolling-load requirements;
- seismic/lateral requirements if applicable;
- bracing requirements;
- corrosion-protection finish;
- pedestal fixing method;
- subfloor condition;
- ramps and steps;
- perimeter details;
- project drawings;
- consultant specification; and
- required manufacturer submittals.
HT Understructure Options Available Through Kayan Gulf
Kayan Gulf supplies raised flooring systems sourced from international manufacturers according to project requirements. Huateng Access Floor is one of Kayan Gulf’s principal manufacturing suppliers and can provide standard and project-specific understructure configurations.
Depending on the approved system and project requirements, available configurations can include:
- flat-head steel pedestals;
- snap-on pedestal heads;
- heavy-duty pedestals;
- low-profile network-floor supports;
- aluminum understructures;
- stringered systems;
- high-floor systems;
- braced/seismic configurations;
- different corrosion-protection finishes; and
- project-specific pedestal/head designs subject to manufacturer feasibility.
Need a Raised Floor Understructure for a Saudi Project?
Send Kayan Gulf your BOQ, panel specification, finished floor height, drawings, equipment loads and project location. We can coordinate the panel and understructure configuration with the applicable manufacturing source and prepare the required project quotation and technical information.
Continue Learning About Raised Flooring
If you are new to the subject, start with our complete guide explaining what a raised floor is .
To compare steel cementitious, HPL, PVC, woodcore, calcium sulphate, aluminum and airflow systems, see our guide to the main types of raised floor systems .
For supply and project enquiries, visit Kayan Gulf’s raised flooring systems in Saudi Arabia page.
Frequently Asked Questions About Raised Floor Pedestals & Stringers
What is a raised floor pedestal?
What is a raised floor stringer?
Does every raised floor need stringers?
What is finished floor height?
How high can raised floor pedestals be?
When are heavy-duty pedestals required?
What is a seismic raised floor pedestal system?
How are raised floor pedestals adjusted?
How are raised floor pedestals fixed to concrete?
What corrosion protection is available for raised floor pedestals?
Can the pedestal understructure be customized?
Can Kayan Gulf supply raised floor pedestals and stringers in Saudi Arabia?
Manufacturer & Technical References
Understructure dimensions and performance vary by product. This guide uses manufacturer documentation as technical examples rather than universal specifications.
- Changzhou Huateng Access Floor Co., Ltd. — HT FS800 HPL Raised Access Floor & HT FS-B-PST Understructure Technical Specification.
- Huateng — Raised Floor Pedestal / Understructures
- Huateng — Raised Floor Installation for Stringer Systems
- Huateng — Raised Access Floor Product Range
Final pedestal, stringer, bracing and fixing selections should follow the approved project specification, manufacturer’s technical submittal and applicable structural requirements.
Need support with a project specification?
Kayan Gulf supplies specialized construction materials for raised floors, expansion joints, fire-rated doors, wall protection systems, drainage solutions, access panels, and related project requirements across Saudi Arabia and the GCC.